US9057836B2 - Infrared absorbing glass wafer and method for producing same - Google Patents

Infrared absorbing glass wafer and method for producing same Download PDF

Info

Publication number
US9057836B2
US9057836B2 US13/846,070 US201313846070A US9057836B2 US 9057836 B2 US9057836 B2 US 9057836B2 US 201313846070 A US201313846070 A US 201313846070A US 9057836 B2 US9057836 B2 US 9057836B2
Authority
US
United States
Prior art keywords
glass
wafer
glass wafer
thickness
millimeters
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US13/846,070
Other versions
US20130264672A1 (en
Inventor
Bianca Schreder
Jochen Freund
Ute Woelfel
Claude Martin
Christophe BAUR
Steffen REICHESL
Marc Clement
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schott AG
Original Assignee
Schott AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schott AG filed Critical Schott AG
Assigned to SCHOTT AG reassignment SCHOTT AG ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BAUR, CHRISTOPHE, MARTIN, CLAUDE, CLEMENT, MARC KARL, FREUND, JOCHEN, REICHEL, STEFFEN, SCHREDER, BIANCA, WOELFEL, UTE
Publication of US20130264672A1 publication Critical patent/US20130264672A1/en
Application granted granted Critical
Publication of US9057836B2 publication Critical patent/US9057836B2/en
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/20Filters
    • G02B5/22Absorbing filters
    • G02B5/226Glass filters
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/12Silica-free oxide glass compositions
    • C03C3/16Silica-free oxide glass compositions containing phosphorus
    • C03C3/17Silica-free oxide glass compositions containing phosphorus containing aluminium or beryllium
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C3/00Glass compositions
    • C03C3/12Silica-free oxide glass compositions
    • C03C3/23Silica-free oxide glass compositions containing halogen and at least one oxide, e.g. oxide of boron
    • C03C3/247Silica-free oxide glass compositions containing halogen and at least one oxide, e.g. oxide of boron containing fluorine and phosphorus
    • CCHEMISTRY; METALLURGY
    • C03GLASS; MINERAL OR SLAG WOOL
    • C03CCHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
    • C03C4/00Compositions for glass with special properties
    • C03C4/08Compositions for glass with special properties for glass selectively absorbing radiation of specified wave lengths
    • C03C4/082Compositions for glass with special properties for glass selectively absorbing radiation of specified wave lengths for infrared absorbing glass
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/20Filters
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/20Filters
    • G02B5/208Filters for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation
    • GPHYSICS
    • G02OPTICS
    • G02BOPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00Optical elements other than lenses
    • G02B5/20Filters
    • G02B5/28Interference filters
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144Devices controlled by radiation
    • H01L27/146Imager structures
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02Details
    • H01L31/0216Coatings
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144Devices controlled by radiation
    • H01L27/146Imager structures
    • H01L27/14601Structural or functional details thereof
    • H01L27/1462Coatings
    • H01L27/14621Colour filter arrangements

Definitions

  • the invention generally relates to glass wafers. More particularly, the invention relates to glass wafers made of infrared absorbing glasses.
  • camera chips typically have the property that the pixels of the chip are sensitive also in the infrared spectral range.
  • the optical system of camera modules whose optical components are made from standard glasses or plastic materials generally exhibit a certain amount of infrared transmission.
  • infrared light that reaches the chip results in undesirable color and brightness distortions.
  • camera modules are typically equipped with infrared filters.
  • the most common infrared filters are interference filters.
  • a multi-layered dielectric layer system is deposited on a substrate, typically a glass substrate.
  • the multi-layered dielectric layer system based on physical reasons, is designed to reflect infrared radiation, but to transmit visible light.
  • Such filters are relatively inexpensive to produce, but have several drawbacks.
  • Interference filters often impart a certain modulation to the transmission curve. This modulation has an effect similar to that of a comb filter and may affect individual colors.
  • interference filters exhibit a much stronger dependency of the filter curve (transmission curve) from the light incident angle than optical filter glass which is also referred to as “colored glass” or as absorption filter.
  • Compact cameras typically have a full opening angle of up to 30° and often are not telecentrically aligned, i.e. the light rays impinge to the image sensor at a certain angle (with the full opening angle).
  • the infrared light is reflected back by the interference layer into the optical system. Since the interference filter generally still exhibits a residual transmission at least in the near infrared range, very annoying ghost images may occur in the optical system due to multiple reflections.
  • infrared filters in form of filter glasses.
  • a filter glass by virtue of its character neither exhibits the aforementioned comb filter effect nor ghost images due to multiple reflected infrared light, since the infrared light is absorbed when passing through the glass.
  • interference filters when compared to filter glasses.
  • the interference layers are very thin and can be deposited on very thin substrates. This has so far allowed to produce more compact optical systems using interference filters.
  • an object of the invention is to simplify the manufacturing of optical systems that include filter glasses as an infrared filter, and to make it cheaper and at the same time to reduce the space required by the filter glass.
  • the invention provides a glass wafer made of a copper ions (Cu ions) containing fluorophosphate or phosphate glass.
  • Cu ions copper ions containing glasses for absorption of infrared light are also referred to as blue glasses.
  • the glass wafer has a diameter greater than 15 centimeters.
  • the thickness of the glass wafer is smaller than 0.4 millimeters.
  • At least one of the surfaces of the glass wafer is polished. Height modulations of the surfaces of the glass wafer in form of waves are limited to a height of less than 200 nanometers, preferably less than 130 nanometers, based on a length of not more than 1 millimeter.
  • Waves having a width smaller than the above-mentioned relevant scale of 1 millimeter are particularly effective with respect to the optical resolution of camera sensors.
  • Relevant herein is the wavelength, or an average period of the waves within a length range from 0.1 to 1 millimeter.
  • the variation in thickness of the glass wafer is smaller than ⁇ 50 ⁇ m, based on a surface area of 5 ⁇ 5 mm, or 25 mm 2 .
  • This slight variation in thickness is advantageous to ensure that the filter curve (transmission curve) remains approximately constant (i.e. varies only slightly). Also this feature of the glass wafer can be achieved by the inventive production method as described below.
  • the thickness of the glass wafer ranges between 0.18 millimeters and 0.32 millimeters, more preferably from not less than 0.2 millimeters to not more than 0.3 millimeters.
  • the glass wafer has a diameter of 8 inches and a thickness of 0.30 mm.
  • the thickness of the glass wafer ranges from 0.08 to 0.15 millimeters, and in particular is about 0.1 millimeters.
  • the aforementioned thickness data do not mean that the thickness of the glass wafer varies between the indicated values. Rather, the glass wafer is of plane-parallel shape, and the uniform thickness of the glass wafer is in a range of the above mentioned values.
  • the infrared filters made from the glass wafer are mounted near the camera chip.
  • the glass wafer preferably has no bubbles and/or inclusions which are larger than 100 nm or larger than 200 nm. Therefore, shadowing effects are virtually negligible, even with small pixels of the camera sensor with pixel sizes down to about 1 ⁇ m.
  • the glass wafer according to the invention absorbs in the infrared range, due to the copper ions contained.
  • the wafer is very thin, having a thickness of less than 0.4 millimeters, and therefore it is well suited especially for the very compact optical systems of small cameras such as incorporated in cell phones.
  • a problem usually arising with thin glasses is a ripple of the glass surface and the uniformity of the glass thickness.
  • this problem is solved by thinning the wafer by an abrasive process from a thicker glass substrate to the thickness of less than 0.4 millimeters.
  • the abrasive process comprises polishing as a sole or in particular as a final step to obtain an appropriate surface.
  • a method for manufacturing the glass wafer comprises the steps of: producing a glass sheet of a copper ions containing phosphate or fluorophosphate glass, the glass sheet having a thickness of at least 1.8 millimeters; removing glass material in an abrasive process, until the glass sheet or the wafer previously produced from the glass sheet has a thickness of not more than 0.4 millimeters, the abrasive process at least comprising polishing the glass sheet or the wafer already produced from the glass sheet.
  • the producing of the wafer from the glass sheet in particular comprises working out the wafer from the glass sheet with its intended outline shape. The working out may for example be accomplished by cutting, sawing, or even grinding, such as by ultrasonic vibration grinding.
  • the wafer is then worked out from the glass sheet following the abrasive process.
  • the glass is thinned by at least a factor of 4.5 by polishing, or by grinding followed by polishing.
  • the method may seem to be complicated at first glance, but in this way a high plane-parallelism of the glass wafer and especially a low curvature (also referred to as “warpage”) can be achieved.
  • the invention also relates to a wafer assembly comprising a glass wafer according to the invention and an optoelectronic functional wafer, or an assembly of a semiconductor wafer having a plurality of optoelectronic array sensors for producing camera modules thereon and a glass wafer according to the invention joint to the semiconductor wafer.
  • the two wafers do not necessarily have to be joint directly. Rather, one or more intermediate layers may be provided between the two wafers. For example, a layer or a wafer with microlenses may be provided between the infrared absorbing glass wafer according to the invention and the functional wafer.
  • FIG. 1 , FIG. 2 , and FIG. 3 illustrate the manufacturing of a glass wafer according to the invention
  • FIG. 4 shows a wafer assembly comprising a semiconductor wafer and an infrared absorbing glass wafer
  • FIG. 5 shows a camera chip including an infrared filter
  • FIG. 6 shows a camera module with an infrared filter
  • FIG. 7 shows a transmission curve of an infrared absorbing glass wafer having a thickness of 0.3 mm.
  • FIG. 1 shows a crucible 14 having a slotted nozzle at its bottom.
  • the crucible may be formed by the melting trough itself, or the fluorophosphate or phosphate glass melt 15 produced in the melting trough is filled into crucible 14 .
  • a strip of glass exiting from slotted nozzle 16 is separated into individual glass sheets 10 using a cutting tool 17 .
  • the glass sheets are manufactured in a so-called downdraw process.
  • other processes are likewise possible, such as a float process or overflow fusion process.
  • the thus produced glass sheets 10 have a thickness of at least 1.8 millimeters, preferably from 1.8 to 3.2 millimeters, more preferably a thickness in a range from 2 to 3 millimeters. With these glass thicknesses, a planar surface and a comparatively uniform thickness is achieved. On the other hand, with glass thicknesses of not more than 3 millimeters, the amount of glass material to be ablated to obtain the intended final thickness is limited.
  • wafer-shaped glass sheets 11 are cut out of glass sheet 10 .
  • these glass sheets 11 are ground down and polished, from the original thickness of at least 1.8 millimeters to a thickness of less than 0.4 millimeters, using one or more ablation tools 19 .
  • the glass wafer 1 so produced has at least one polished surface 3 .
  • glass material is removed from both sides, so that the two opposite surfaces 3 , 5 of glass wafer 1 are polished.
  • a polishing plate may be used, for example, and a suitable abrasive agent, such as a cerium oxide slurry.
  • the glass wafer 1 is cut out of the glass sheet 10 prior to polishing. This is advantageous in order to reduce the amount of material to be removed. However, it is likewise possible to perform some ablation steps prior to cutting. Furthermore, it is also possible to cut out a preform, to thin the glass to the intended thickness, and then to cut out the final shape of the wafer. This may be advantageous in terms of avoiding any inhomogeneities at the edge of glass wafer 1 that might be caused by the ablation process.
  • the glass sheets are made to have as few streaks as possible.
  • Streaks also referred to as schlieren in the art, cause inhomogeneities in the refractive index.
  • schlieren do not significantly affect the optical properties of the camera module when the infrared filter produced from glass wafer 1 is positioned close to the sensor.
  • This arrangement in principle, is a common arrangement for camera modules.
  • the schlieren represent local chemical and/or mechanical changes in the glass. These modifications are generally accompanied by an alteration in strength. In the grinding process, this may cause that the schlieren are reflected in unevennesses during polishing of the glass.
  • the effect of the schlieren on the optical path of light passing through the volume of the glass is relatively small due to the only small local change of the refractive index.
  • surface modulations caused by internal glass schlieren are smaller than 200 nm, more preferably smaller than 130 nm.
  • a phosphate or fluorophosphate glass according to the invention in combination with the abrasive removal allows to avoid this effect and at the same time permits to produce a very thin, large area glass wafer 1 of a homogenous thickness.
  • bubbles and/or inclusions in the glass should be smaller than 200 nm, more preferably smaller than 100 nm in order to ensure a good image quality of the camera chip by avoiding shadowing effects.
  • Copper containing phosphate or fluorophosphate glasses of a chemical composition comprising the following components (wt. % based on oxide) have been found suitable for the invention: P 2 O 5 : 25-80; Al 2 O 3 : 1-13; B 2 O 3 : 0-3; Li 2 O: 0-13; Na 2 O: 0-10; K 2 O: 0-11; CaO: 0-16; BaO: 0-26; SrO: 0-16; MgO: 1-10; ZnO: 0-10; CuO: 1-7.
  • at least two of alkaline earth oxides CaO, BaO, SrO, and MgO are used in the glass composition.
  • As 2 O 3 is optional, as a refining agent. When using As 2 O 3 , the content thereof is preferably up to 0.02 weight percent.
  • fluorine contained in the glass is useful in terms of corrosion resistance and weather resistance, fluorophosphate glasses are preferred according to one embodiment of the invention.
  • FIG. 4 shows a wafer assembly 13 comprising a glass wafer 1 according to the invention and a semiconductor wafer 12 having a plurality of camera sensors 22 thereon, wherein glass wafer 1 is bounded to semiconductor wafer 12 on the side of semiconductor wafer 12 on which the camera sensors 22 are arranged.
  • Semiconductor wafer 12 also has a diameter of more than 15 cm, like glass wafer 1 .
  • FIG. 5 illustrates an exemplary embodiment of a camera chip having optical functional layers, such as obtainable by separation from the wafer assembly 13 .
  • a window 27 with microlenses is applied upon camera chip 25 on the side thereof on which the optoelectronic array sensor 22 is arranged.
  • the infrared filter 29 made from glass wafer 1 is disposed.
  • an optical low-pass filter 31 is used.
  • this optical low-pass filter 31 is mounted to infrared filter 29 .
  • Optical low-pass filter 31 serves to avoid moiré patterns in the captured images, which occur when recording periodic structures whose periodicity corresponds to the pixel pitch.
  • Low-pass filter 31 may also be attached to glass wafer 1 of wafer assembly 13 in form of a wafer and may then be separated together with camera chip 25 and infrared filter 27 by being cut from the wafer assembly 13 .
  • FIG. 6 shows a camera module 32 comprising an objective lens 33 which focuses incident beams of rays 39 onto optoelectronic array sensor 22 by means of lenses 34 , 35 , 36 , 37 .
  • schlieren existing in the glass of infrared filter 29 will cause a difference of the optical paths due to local variations of the refractive index
  • the effect of schlieren may be simulated by a deformation of the surface of infrared filter 29 , which causes a corresponding path difference.
  • surface 3 of infrared filter 29 cut from glass wafer 1 is shown as being wavy.
  • the height of waves 100 is exaggerated.
  • Waves 100 on the surface which have been imparted by schlieren, locally cause an additional negative or positive refractive power.
  • a result thereof is that the respective beam of rays is no longer focused exactly onto the light sensitive surface of array sensor 22 . Accordingly, there will be a loss in maximum possible spatial resolution.
  • This negative effect is avoided or at least alleviated by using an infrared filter made from a glass wafer 1 according to the invention, which is produced by mechanically thinning a low schlieren phosphate glass, preferably fluorophosphate glass.
  • the surface modulation caused by waves 100 resulting from schlieren is smaller than 200 nanometers, preferably smaller than 130 nanometers. This height indication represents a peak-to-valley value.
  • the relevant surface scale for the waves is a length range of up to 1 millimeter, typically a length range from 0.1 to 1 millimeter.
  • wave structures having an average periodicity or width transversely to the longitudinal direction of the waves of not more than 1 millimeter.
  • the thickness variation of glass wafer 1 is less than 50 ⁇ m, based on a surface area of 25 mm 2 , so that the transmission curve remains approximately constant.
  • FIG. 7 shows, as an exemplary embodiment, a transmission curve of a copper ions containing fluorophosphate glass (in this case a glass marketed under the trade name BG60 of SCHOTT AG and having a thickness of 0.3 mm), such as it may be used for the invention.
  • a copper ions containing fluorophosphate glass in this case a glass marketed under the trade name BG60 of SCHOTT AG and having a thickness of 0.3 mm
  • the transmission of the glass significantly decreases at wavelengths above the maximum red sensitivity of the human eye at 560 nanometers, due to an absorption of the copper ions. In the visible spectral range at shorter wavelengths, transmission is relatively constant. If a higher copper content is selected, the drop of transmission at wavelengths above 560 nanometers will be even steeper.
  • glass wafer 1 may have further layers.
  • an optical anti-reflection coating is possible, and/or a combination with an additional dielectric interference layer system for reflecting infrared components.

Landscapes

  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Optics & Photonics (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electromagnetism (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Hardware Design (AREA)
  • Toxicology (AREA)
  • Health & Medical Sciences (AREA)
  • Glass Compositions (AREA)
  • Solid State Image Pick-Up Elements (AREA)
  • Optical Filters (AREA)
  • Surface Treatment Of Glass (AREA)

Abstract

A glass wafer is provided that is made of a copper ions containing phosphate or fluorophosphate glass. The glass wafer has a diameter greater than 15 centimeters and a thickness of less than 0.4 millimeters. The glass wafer has two plane-parallel surfaces at least one of which is polished.

Description

CROSS REFERENCE TO RELATED APPLICATIONS
This application claims benefit under 35 U.S.C. §119(a) of German Patent Application No. De 10 2012 103 077.4, filed Apr. 10, 2012, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to glass wafers. More particularly, the invention relates to glass wafers made of infrared absorbing glasses.
2. Description of Related Art
As is known, camera chips typically have the property that the pixels of the chip are sensitive also in the infrared spectral range. Moreover, the optical system of camera modules whose optical components are made from standard glasses or plastic materials generally exhibit a certain amount of infrared transmission. However, infrared light that reaches the chip results in undesirable color and brightness distortions.
For this reason, camera modules are typically equipped with infrared filters. The most common infrared filters are interference filters. For such filters, a multi-layered dielectric layer system is deposited on a substrate, typically a glass substrate. The multi-layered dielectric layer system, based on physical reasons, is designed to reflect infrared radiation, but to transmit visible light. Such filters are relatively inexpensive to produce, but have several drawbacks. Interference filters often impart a certain modulation to the transmission curve. This modulation has an effect similar to that of a comb filter and may affect individual colors.
Moreover, interference filters exhibit a much stronger dependency of the filter curve (transmission curve) from the light incident angle than optical filter glass which is also referred to as “colored glass” or as absorption filter. Compact cameras typically have a full opening angle of up to 30° and often are not telecentrically aligned, i.e. the light rays impinge to the image sensor at a certain angle (with the full opening angle).
Additionally, the infrared light is reflected back by the interference layer into the optical system. Since the interference filter generally still exhibits a residual transmission at least in the near infrared range, very annoying ghost images may occur in the optical system due to multiple reflections.
An alternative thereto is provided by infrared filters in form of filter glasses. A filter glass, by virtue of its character neither exhibits the aforementioned comb filter effect nor ghost images due to multiple reflected infrared light, since the infrared light is absorbed when passing through the glass.
However, heretofore, their cost-efficient manufacturing is not the only advantage of interference filters when compared to filter glasses. The interference layers are very thin and can be deposited on very thin substrates. This has so far allowed to produce more compact optical systems using interference filters.
SUMMARY
Therefore, an object of the invention is to simplify the manufacturing of optical systems that include filter glasses as an infrared filter, and to make it cheaper and at the same time to reduce the space required by the filter glass.
Accordingly, the invention provides a glass wafer made of a copper ions (Cu ions) containing fluorophosphate or phosphate glass. Such copper ions containing glasses for absorption of infrared light are also referred to as blue glasses. The glass wafer has a diameter greater than 15 centimeters. The thickness of the glass wafer is smaller than 0.4 millimeters. At least one of the surfaces of the glass wafer is polished. Height modulations of the surfaces of the glass wafer in form of waves are limited to a height of less than 200 nanometers, preferably less than 130 nanometers, based on a length of not more than 1 millimeter. Waves having a width smaller than the above-mentioned relevant scale of 1 millimeter are particularly effective with respect to the optical resolution of camera sensors. Relevant herein is the wavelength, or an average period of the waves within a length range from 0.1 to 1 millimeter.
Additionally, according to one embodiment of the invention, the variation in thickness of the glass wafer is smaller than ±50 μm, based on a surface area of 5×5 mm, or 25 mm2. This slight variation in thickness is advantageous to ensure that the filter curve (transmission curve) remains approximately constant (i.e. varies only slightly). Also this feature of the glass wafer can be achieved by the inventive production method as described below.
Preferably, the thickness of the glass wafer ranges between 0.18 millimeters and 0.32 millimeters, more preferably from not less than 0.2 millimeters to not more than 0.3 millimeters. According to one exemplary embodiment, the glass wafer has a diameter of 8 inches and a thickness of 0.30 mm.
According to another embodiment, the thickness of the glass wafer ranges from 0.08 to 0.15 millimeters, and in particular is about 0.1 millimeters.
Of course, the aforementioned thickness data do not mean that the thickness of the glass wafer varies between the indicated values. Rather, the glass wafer is of plane-parallel shape, and the uniform thickness of the glass wafer is in a range of the above mentioned values.
Typically, the infrared filters made from the glass wafer are mounted near the camera chip. In order to avoid shadowing effects on the camera chip, the glass wafer preferably has no bubbles and/or inclusions which are larger than 100 nm or larger than 200 nm. Therefore, shadowing effects are virtually negligible, even with small pixels of the camera sensor with pixel sizes down to about 1 μm.
The glass wafer according to the invention absorbs in the infrared range, due to the copper ions contained.
The wafer is very thin, having a thickness of less than 0.4 millimeters, and therefore it is well suited especially for the very compact optical systems of small cameras such as incorporated in cell phones.
However, a problem usually arising with thin glasses is a ripple of the glass surface and the uniformity of the glass thickness. According to the invention, this problem is solved by thinning the wafer by an abrasive process from a thicker glass substrate to the thickness of less than 0.4 millimeters. The abrasive process comprises polishing as a sole or in particular as a final step to obtain an appropriate surface.
Specifically, a method for manufacturing the glass wafer is provided, which comprises the steps of: producing a glass sheet of a copper ions containing phosphate or fluorophosphate glass, the glass sheet having a thickness of at least 1.8 millimeters; removing glass material in an abrasive process, until the glass sheet or the wafer previously produced from the glass sheet has a thickness of not more than 0.4 millimeters, the abrasive process at least comprising polishing the glass sheet or the wafer already produced from the glass sheet. The producing of the wafer from the glass sheet in particular comprises working out the wafer from the glass sheet with its intended outline shape. The working out may for example be accomplished by cutting, sawing, or even grinding, such as by ultrasonic vibration grinding.
According to an alternative of the method, if the glass sheet at the end of the abrasive process still does not possess the final outline shape of the wafer, the wafer is then worked out from the glass sheet following the abrasive process.
According to the thicknesses indicated above, for manufacturing the wafer the glass is thinned by at least a factor of 4.5 by polishing, or by grinding followed by polishing. The method may seem to be complicated at first glance, but in this way a high plane-parallelism of the glass wafer and especially a low curvature (also referred to as “warpage”) can be achieved.
This now allows to join the wafer with a functional wafer having camera chips disposed thereon, or with optoelectronic array sensors, and then to separate the chips to produce camera modules. Accordingly, the invention also relates to a wafer assembly comprising a glass wafer according to the invention and an optoelectronic functional wafer, or an assembly of a semiconductor wafer having a plurality of optoelectronic array sensors for producing camera modules thereon and a glass wafer according to the invention joint to the semiconductor wafer. The two wafers do not necessarily have to be joint directly. Rather, one or more intermediate layers may be provided between the two wafers. For example, a layer or a wafer with microlenses may be provided between the infrared absorbing glass wafer according to the invention and the functional wafer.
DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail by way of exemplary embodiments and with reference to the accompanying figures. In the figures, the same reference numerals designate the same or corresponding elements. In the figures:
FIG. 1, FIG. 2, and FIG. 3 illustrate the manufacturing of a glass wafer according to the invention;
FIG. 4 shows a wafer assembly comprising a semiconductor wafer and an infrared absorbing glass wafer;
FIG. 5 shows a camera chip including an infrared filter;
FIG. 6 shows a camera module with an infrared filter; and
FIG. 7 shows a transmission curve of an infrared absorbing glass wafer having a thickness of 0.3 mm.
DETAILED DESCRIPTION
Referring to FIGS. 1, 2, and 3, the manufacturing of a glass wafer according to the invention will be described schematically. First, the molten glass from which the glass sheet is produced, is prepared by a preferably continuous melting process. FIG. 1 shows a crucible 14 having a slotted nozzle at its bottom. The crucible may be formed by the melting trough itself, or the fluorophosphate or phosphate glass melt 15 produced in the melting trough is filled into crucible 14. A strip of glass exiting from slotted nozzle 16 is separated into individual glass sheets 10 using a cutting tool 17. Accordingly, in this exemplary embodiment the glass sheets are manufactured in a so-called downdraw process. Alternatively, however, other processes are likewise possible, such as a float process or overflow fusion process.
The thus produced glass sheets 10 have a thickness of at least 1.8 millimeters, preferably from 1.8 to 3.2 millimeters, more preferably a thickness in a range from 2 to 3 millimeters. With these glass thicknesses, a planar surface and a comparatively uniform thickness is achieved. On the other hand, with glass thicknesses of not more than 3 millimeters, the amount of glass material to be ablated to obtain the intended final thickness is limited.
Subsequently, as shown in FIG. 2, wafer-shaped glass sheets 11 are cut out of glass sheet 10.
Then, as shown in FIG. 3, these glass sheets 11 are ground down and polished, from the original thickness of at least 1.8 millimeters to a thickness of less than 0.4 millimeters, using one or more ablation tools 19. Accordingly, the glass wafer 1 so produced has at least one polished surface 3. Preferably, glass material is removed from both sides, so that the two opposite surfaces 3, 5 of glass wafer 1 are polished. For polishing, a polishing plate may be used, for example, and a suitable abrasive agent, such as a cerium oxide slurry.
In the exemplary embodiment schematically illustrated in FIGS. 1 to 3, the glass wafer 1 is cut out of the glass sheet 10 prior to polishing. This is advantageous in order to reduce the amount of material to be removed. However, it is likewise possible to perform some ablation steps prior to cutting. Furthermore, it is also possible to cut out a preform, to thin the glass to the intended thickness, and then to cut out the final shape of the wafer. This may be advantageous in terms of avoiding any inhomogeneities at the edge of glass wafer 1 that might be caused by the ablation process.
Generally, cutting out the wafer prior to the abrasive removal of material is advantageous, since the oddments may be recycled as fragments for the manufacturing of glass, thus protecting resources (environmental, costs, raw material).
Preferably, the glass sheets are made to have as few streaks as possible. Streaks, also referred to as schlieren in the art, cause inhomogeneities in the refractive index. However, to a certain degree such schlieren do not significantly affect the optical properties of the camera module when the infrared filter produced from glass wafer 1 is positioned close to the sensor. This arrangement, in principle, is a common arrangement for camera modules.
However, there is another effect that may adversely affect the optical properties. The schlieren represent local chemical and/or mechanical changes in the glass. These modifications are generally accompanied by an alteration in strength. In the grinding process, this may cause that the schlieren are reflected in unevennesses during polishing of the glass. The effect of the schlieren on the optical path of light passing through the volume of the glass is relatively small due to the only small local change of the refractive index.
However, on the surface of the glass this turns out to be different. If schlieren are produced at the surface, these will lead to local variations in thickness, which now cause a significant effect on the beam path and may adversely affect the resolution of the camera module, since waves on the glass surface produced at the schlieren during polishing will act like lenses.
Therefore, in an wafer according to the invention, surface modulations caused by internal glass schlieren are smaller than 200 nm, more preferably smaller than 130 nm.
However, the use of a phosphate or fluorophosphate glass according to the invention in combination with the abrasive removal allows to avoid this effect and at the same time permits to produce a very thin, large area glass wafer 1 of a homogenous thickness.
Additionally, bubbles and/or inclusions in the glass should be smaller than 200 nm, more preferably smaller than 100 nm in order to ensure a good image quality of the camera chip by avoiding shadowing effects.
Copper containing phosphate or fluorophosphate glasses of a chemical composition comprising the following components (wt. % based on oxide) have been found suitable for the invention:
P2O5: 25-80;
Al2O3: 1-13;
B2O3: 0-3;
Li2O: 0-13;
Na2O: 0-10;
K2O: 0-11;
CaO: 0-16;
BaO: 0-26;
SrO: 0-16;
MgO: 1-10;
ZnO: 0-10;
CuO: 1-7.
In deviating from the composition given above, not all oxides of the alkaline earth oxides listed above need to be contained. Preferably, however, at least two of alkaline earth oxides CaO, BaO, SrO, and MgO are used in the glass composition.
According to one embodiment, the following fluorophosphate glasses are preferred, with a chemical composition comprising the following components (in wt. % based on oxide):
P2O5: 25-60;
Al2O3: 1-13;
Li2O: 0-13;
Na2O: 0-10;
K2O: 0-11;
MgO: 1-10;
CaO: 1-16;
BaO: 1-26;
SrO: 0-16;
ZnO: 0-10;
CuO: 1-7;
ΣRO (R=Mg, Ca, Sr, Ba) 15-40;
ΣR2O (R=Li, Na, K) 3-18;
wherein starting from this composition, 1 to 39 mol % of the oxide ions (O2−) in the glass are replaced by fluoride ions (F).
As2O3 is optional, as a refining agent. When using As2O3, the content thereof is preferably up to 0.02 weight percent.
Since it has been found that fluorine contained in the glass is useful in terms of corrosion resistance and weather resistance, fluorophosphate glasses are preferred according to one embodiment of the invention.
The thin glass wafer 1 produced according to the invention now furthermore enables to produce camera modules or at least camera sensors which include an infrared filter at wafer level. FIG. 4 shows a wafer assembly 13 comprising a glass wafer 1 according to the invention and a semiconductor wafer 12 having a plurality of camera sensors 22 thereon, wherein glass wafer 1 is bounded to semiconductor wafer 12 on the side of semiconductor wafer 12 on which the camera sensors 22 are arranged. Semiconductor wafer 12 also has a diameter of more than 15 cm, like glass wafer 1.
Since by removing glass material in an abrasive process, large glass wafers 1 can be produced, it is also possible to use correspondingly large semiconductor wafers 12 with a correspondingly large number of camera sensors 22 arranged thereon. The individual camera chips with camera sensors 22 may then be separated from the wafer assembly 13 by dicing or sawing.
As already mentioned above, glass wafer 1 does not need to be bonded directly to semiconductor wafer 12 in the wafer assembly, rather, further wafers or intermediate layers may be interposed. FIG. 5 illustrates an exemplary embodiment of a camera chip having optical functional layers, such as obtainable by separation from the wafer assembly 13. In the illustrated example, a window 27 with microlenses is applied upon camera chip 25 on the side thereof on which the optoelectronic array sensor 22 is arranged. Upon this window 27, the infrared filter 29 made from glass wafer 1 is disposed.
Finally, advantageously, an optical low-pass filter 31 is used. In the example shown in FIG. 5, this optical low-pass filter 31 is mounted to infrared filter 29. Optical low-pass filter 31 serves to avoid moiré patterns in the captured images, which occur when recording periodic structures whose periodicity corresponds to the pixel pitch. Low-pass filter 31 may also be attached to glass wafer 1 of wafer assembly 13 in form of a wafer and may then be separated together with camera chip 25 and infrared filter 27 by being cut from the wafer assembly 13.
It will now be illustrated by way of an exemplary embodiment how schlieren and also corresponding surface deformations of an infrared filter may affect the resolution of a camera module. For this purpose, FIG. 6 shows a camera module 32 comprising an objective lens 33 which focuses incident beams of rays 39 onto optoelectronic array sensor 22 by means of lenses 34, 35, 36, 37.
Since schlieren existing in the glass of infrared filter 29 will cause a difference of the optical paths due to local variations of the refractive index, the effect of schlieren may be simulated by a deformation of the surface of infrared filter 29, which causes a corresponding path difference. For illustration purposes, surface 3 of infrared filter 29 cut from glass wafer 1 is shown as being wavy. Of course, for the purpose of illustration, the height of waves 100 is exaggerated.
Waves 100 on the surface, which have been imparted by schlieren, locally cause an additional negative or positive refractive power. In both cases, a result thereof is that the respective beam of rays is no longer focused exactly onto the light sensitive surface of array sensor 22. Accordingly, there will be a loss in maximum possible spatial resolution. This negative effect is avoided or at least alleviated by using an infrared filter made from a glass wafer 1 according to the invention, which is produced by mechanically thinning a low schlieren phosphate glass, preferably fluorophosphate glass. The surface modulation caused by waves 100 resulting from schlieren is smaller than 200 nanometers, preferably smaller than 130 nanometers. This height indication represents a peak-to-valley value. The relevant surface scale for the waves is a length range of up to 1 millimeter, typically a length range from 0.1 to 1 millimeter. In other words, we speak of wave structures having an average periodicity or width transversely to the longitudinal direction of the waves of not more than 1 millimeter.
In addition, preferably, the thickness variation of glass wafer 1 is less than 50 μm, based on a surface area of 25 mm2, so that the transmission curve remains approximately constant.
FIG. 7 shows, as an exemplary embodiment, a transmission curve of a copper ions containing fluorophosphate glass (in this case a glass marketed under the trade name BG60 of SCHOTT AG and having a thickness of 0.3 mm), such as it may be used for the invention. As is apparent from the curve, the transmission of the glass significantly decreases at wavelengths above the maximum red sensitivity of the human eye at 560 nanometers, due to an absorption of the copper ions. In the visible spectral range at shorter wavelengths, transmission is relatively constant. If a higher copper content is selected, the drop of transmission at wavelengths above 560 nanometers will be even steeper.
It will be apparent to those skilled in the art that the invention is not limited to the exemplary embodiments illustrated in the figures but may be varied in various ways within the scope of the appended claims. For example, glass wafer 1 may have further layers. For example, an optical anti-reflection coating is possible, and/or a combination with an additional dielectric interference layer system for reflecting infrared components.
LIST OF REFERENCE NUMERALS
  • 1 Glass wafer
  • 3, 5 Surfaces of glass wafer
  • 10 Glass sheet
  • 11 Wafer-shaped glass sheet
  • 12 Semiconductor wafer
  • 13 Wafer assembly
  • 14 Crucible
  • 15 Glass melt
  • 16 Slotted nozzle
  • 17 Separating tool
  • 19 Ablation tool
  • 22 Camera sensor
  • 25 Camera chip
  • 27 Window with microlenses
  • 29 Infrared filter
  • 31 Optical low-pass filter
  • 32 Camera module
  • 33 Objective lens
  • 34, 35, 36, 37 Lenses of 33
  • 39 Beam of rays
  • 100 Waves on surface of 1

Claims (9)

What is claimed is:
1. A glass wafer comprising:
a copper ions containing phosphate or fluorophosphate glass;
a diameter greater than 15 centimeters and a thickness of less than 0.4 millimeters; and
two plane-parallel surfaces, at least one of the two plane-parallel surfaces being polished, wherein the two plane-parallel surfaces have height modulations in form of waves with a height of less than 200 nanometers based on a length of not more than 1 millimeter.
2. The glass wafer as claimed in claim 1, wherein the height is less than 130 nanometers.
3. The glass wafer as claimed in claim 1, wherein the thickness varies by less than ±50 μm based on a surface area of 25 mm2.
4. The glass wafer as claimed in claim 3, wherein the thickness ranges between 0.18 millimeters and 0.32 millimeters.
5. The glass wafer as claimed in claim 1, further comprising bubbles and inclusions that are no larger than 200 nm.
6. The glass wafer as claimed in claim 1, wherein the bubbles and inclusions that are no larger than 100 nm.
7. The glass wafer as claimed in claim 1, comprising a composition, in weight percent, based on oxide of:

P2O5: 25-80;

Al2O3: 1-13;

B2O3: 0-3;

Li2O: 0-13;

Na2O: 0-10;

K2O: 0-11;

MgO: 1-10;

CaO: 0-16;

BaO: 0-26;

SrO: 0-16;

ZnO: 0-10; and

CuO: 1-7.
8. The glass wafer as claimed in claim 1, comprising a composition, in weight percent, based on oxide of:

P2O5: 25-60;

Al2O3: 1-13;

Li2O: 0-13;

Na2O: 0-10;

K2O: 0-11;

MgO: 1-10;

CaO: 1-16;

BaO: 1-26;

SrO: 0-16;

ZnO: 0-10;

CuO: 1-7;

ΣRO (R=Mg, Ca, Sr, Ba) 15-40; and

ΣR2O (R=Li, Na, K) 3-18;
wherein starting from the composition, 1 to 39 mol % of the oxide ions (O2−) in the glass are replaced by fluoride ions (F).
9. An assembly comprising:
a glass wafer of a copper ions containing phosphate or fluorophosphate glass, the glass wafer having a diameter greater than 15 centimeters and a thickness of less than 0.4 millimeters, the glass wafer having two plane-parallel surfaces at least one of which is polished, the two plane-parallel surfaces having height modulations in form of waves with a height of less than 200 nanometers based on a length of not more than 1 millimeter; and
a semiconductor wafer with a plurality of optoelectronic array sensors for manufacturing camera modules, the glass wafer being bound to the semiconductor wafer.
US13/846,070 2012-04-10 2013-03-18 Infrared absorbing glass wafer and method for producing same Active 2033-06-03 US9057836B2 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE102012103077.4A DE102012103077B4 (en) 2012-04-10 2012-04-10 Infrared absorbing glass wafer and process for its production
DE102012103077 2012-04-10
DE10-2012-103-077.4 2012-04-10

Publications (2)

Publication Number Publication Date
US20130264672A1 US20130264672A1 (en) 2013-10-10
US9057836B2 true US9057836B2 (en) 2015-06-16

Family

ID=49209849

Family Applications (1)

Application Number Title Priority Date Filing Date
US13/846,070 Active 2033-06-03 US9057836B2 (en) 2012-04-10 2013-03-18 Infrared absorbing glass wafer and method for producing same

Country Status (6)

Country Link
US (1) US9057836B2 (en)
JP (1) JP2013216568A (en)
KR (1) KR102140841B1 (en)
CN (1) CN103359938B (en)
DE (1) DE102012103077B4 (en)
TW (1) TWI597252B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10703669B2 (en) 2017-04-28 2020-07-07 Schott Ag Filter gas

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014106698B4 (en) * 2014-05-13 2015-12-24 Schott Ag Optical filter device and method for its production
CN107077046A (en) * 2014-10-20 2017-08-18 肖特玻璃科技(苏州)有限公司 Optical system for camera model, the camera model with optical system and the method for manufacturing optical system
JP6811053B2 (en) * 2016-04-11 2021-01-13 日本電気硝子株式会社 Infrared absorbing glass plate and its manufacturing method, and solid-state image sensor device
TWI771375B (en) * 2017-02-24 2022-07-21 美商康寧公司 High aspect ratio glass wafer
US20190169059A1 (en) * 2017-12-04 2019-06-06 Corning Incorporated Methods for forming thin glass sheets
DE102021112723A1 (en) * 2021-05-17 2022-11-17 Schott Ag Optical system for periscope camera module

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6252702B1 (en) * 1996-06-08 2001-06-26 Avimo Limited Infra red filter
US20040082460A1 (en) * 2002-07-05 2004-04-29 Hoya Corporation Near-infrared light-absorbing glass, near-infrared light-absorbing element, near-infrared light-absorbing filter, and method of manufacturing near-infrared light-absorbing formed glass article, and copper-containing glass
DE102006032047A1 (en) 2006-07-10 2008-01-24 Schott Ag Optoelectronic component e.g. image signal-detecting component, manufacturing method for e.g. digital fixed image camera, involves positioning components either one by one or in groups relative to position of associated components of wafer

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2003081659A (en) * 2001-09-07 2003-03-19 Olympus Optical Co Ltd Method of manufacturing optical element
JP4169545B2 (en) * 2002-07-05 2008-10-22 Hoya株式会社 Near-infrared light absorbing glass, near-infrared light absorbing element, near-infrared light absorbing filter, and method for producing near-infrared light absorbing glass molded body
US8865271B2 (en) * 2003-06-06 2014-10-21 Neophotonics Corporation High rate deposition for the formation of high quality optical coatings
JP4744795B2 (en) * 2003-09-04 2011-08-10 Hoya株式会社 Preform for precision press molding and manufacturing method thereof, optical element and manufacturing method thereof
JP2005213091A (en) * 2004-01-29 2005-08-11 Hoya Corp Method for manufacturing glass optical element
US20080132150A1 (en) * 2006-11-30 2008-06-05 Gregory John Arserio Polishing method for extreme ultraviolet optical elements and elements produced using the method
JP5439903B2 (en) * 2008-03-31 2014-03-12 旭硝子株式会社 Plate-shaped optical glass and end-face processing method for plate-shaped optical glass
JP2011093757A (en) * 2009-10-30 2011-05-12 Hoya Corp Fluorophosphate glass, near infrared ray absorbing filter, optical element, and glass window for semiconductor image sensor
JP2011132077A (en) * 2009-12-25 2011-07-07 Hoya Corp Near-infrared light absorbing glass, near-infrared light absorbing filter, and imaging device
JP5862566B2 (en) * 2010-08-03 2016-02-16 旭硝子株式会社 Near-infrared cut filter glass and manufacturing method thereof

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6252702B1 (en) * 1996-06-08 2001-06-26 Avimo Limited Infra red filter
US20040082460A1 (en) * 2002-07-05 2004-04-29 Hoya Corporation Near-infrared light-absorbing glass, near-infrared light-absorbing element, near-infrared light-absorbing filter, and method of manufacturing near-infrared light-absorbing formed glass article, and copper-containing glass
DE102006032047A1 (en) 2006-07-10 2008-01-24 Schott Ag Optoelectronic component e.g. image signal-detecting component, manufacturing method for e.g. digital fixed image camera, involves positioning components either one by one or in groups relative to position of associated components of wafer

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Office Action dated Dec. 17, 2012 corresponding to German Patent Application No. 10 2012 103 077.4.

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10703669B2 (en) 2017-04-28 2020-07-07 Schott Ag Filter gas

Also Published As

Publication number Publication date
TW201343593A (en) 2013-11-01
CN103359938B (en) 2016-08-24
KR20130115152A (en) 2013-10-21
US20130264672A1 (en) 2013-10-10
DE102012103077A1 (en) 2013-10-10
JP2013216568A (en) 2013-10-24
DE102012103077B4 (en) 2017-06-22
CN103359938A (en) 2013-10-23
TWI597252B (en) 2017-09-01
KR102140841B1 (en) 2020-08-04

Similar Documents

Publication Publication Date Title
US9057836B2 (en) Infrared absorbing glass wafer and method for producing same
US10683233B2 (en) Light selective transmission type glass and laminated substrate
JP5126111B2 (en) Near-infrared cut filter glass and manufacturing method thereof
US20150321942A1 (en) Cutting method for glass substrate, glass substrate, near-infrared cut filter glass, manufacturing method for glass substrate
TWI393687B (en) Glass cover for solid state image sensor and method for manufacturing the same
US20170036304A1 (en) Optical glass and method of cutting glass substrate
CN108367966B (en) Infrared absorbing glass plate, method for manufacturing same, and solid-state imaging element apparatus
US20090203513A1 (en) Glass member for optical parts and glass composition used therefor
TWI791530B (en) Infrared-absorbing glass plate, manufacturing method thereof, and solid-state imaging device
JP5407490B2 (en) Window glass for solid-state image sensor package
JP2007043063A (en) Package for storing solid state imaging device, substrate for mounting the device, and solid state imaging apparatus
KR101920100B1 (en) Glass substrate cutting method and optical glass for solid-state image capturing device
KR20180016374A (en) Glass plate and manufacturing method of glass plate
JP5036229B2 (en) Visibility correction filter glass and visibility correction filter
TWI753884B (en) Infrared absorbing glass plate, method for manufacturing the same, and solid-state imaging element device
KR20170076667A (en) Glass and glass manufacturing method
CN203551813U (en) Near-infrared cut-off filter
US20160197112A1 (en) Optical glass
KR20180041133A (en) Glass plate
US20230367050A1 (en) Near-infrared cut filter and imaging device having same
TW202421597A (en) Optical glass, optical element, glass preform for press molding, and optical device
JP2014116875A (en) Imaging optical system and imaging device
JP2014066943A (en) Optical low-pass filter

Legal Events

Date Code Title Description
AS Assignment

Owner name: SCHOTT AG, GERMANY

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:SCHREDER, BIANCA;FREUND, JOCHEN;WOELFEL, UTE;AND OTHERS;SIGNING DATES FROM 20130613 TO 20130625;REEL/FRAME:030913/0212

STCF Information on status: patent grant

Free format text: PATENTED CASE

FEPP Fee payment procedure

Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 4

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 8TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1552); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 8